Objective: This study aimed to investigate the association between paraspinal muscle measurements using chest computed tomography (CT) and the clinical outcomes of elderly patients with community-acquired pneumonia (CAP).
Methods: This was a single-center, retrospective, observational study that included elderly (≥65 years) patients with CAP hospitalized through an emergency department between March 2020 and December 2022. We collected their baseline characteristics and laboratory data at the time of admission. Paraspinal muscle index and attenuation were calculated at the level of the 12th thoracic vertebra using chest CT taken within 48 hours before and after admission. Univariable and multivariable logistic regression analyses were conducted to evaluate the association between paraspinal muscle measurements and 28-day mortality. Receiver operating characteristic (ROC) curve and area under the curve (AUC) analyses were used to evaluate the prognostic predictive power.
Results: Of 338 enrolled patients, 60 (17.8%) died within 28 days after admission. A high paraspinal muscle index was associated with a low 28-day mortality in elderly patients with CAP (adjusted odds ratio, 0.994; 95% confidence interval, 0.992-0.997). The area under the ROC curve for the muscle index was 0.75, which outperformed pneumonia severity index (PSI) and confusion, urea, respiratory rate, blood pressure, age ≥ 65 (CURB-65), both of which showed 0.64 in predicting mortality.
Conclusion: A high paraspinal muscle index was associated with a low 28-day mortality in patients aged 65 years or older with CAP.
Keywords: Emergency departments; Paraspinal muscle index; Prognosis; Pneumonia.